Investments (Details 6) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Asset derivatives:
Derivatives Asset, Net Amount	$ 4,534	$ 2,501
Free-standing derivatives [Member]
Asset derivatives:
Derivatives Asset, Gross Amounts	4,534	2,501
Derivatives Asset, Gross Amounts Offset in the Consolidated Balance Sheets	0	0
Derivatives Asset, Net Amounts of Assets/Liabilities Presented in the Consolidated Balance Sheets	4,534	2,501
Derivatives Asset, Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments	0	0
Derivatives Asset, Gross Amounts Not Offset in the Consolidated Balance Sheets, Cash Collateral Received	4,770	2,617
Derivatives Asset, Net Amount	$ (236)	$ (116)